Ecg monitoring system with configurable alarm limits

ABSTRACT

An ECG monitoring system for ambulatory patients includes a small multi-electrode patch that adhesively attaches to the chest of a patient. A reusable battery-powered ECG monitor clips onto the patch and receives patient electrical signals from the electrodes of the patch. A processor continuously processes received ECG signals and analyzes the received ECG signals for pre-defined arrhythmia. If an arrhythmia is detected, a wireless transceiver in the ECG monitor transmits the event information and an ECG strip to a monitoring center. At the commencement of a monitoring procedure a message is sent to the monitoring center and configuration information for arrhythmia detection is down-loaded and installed in the monitor. The configuration file is determined by a screen of selectable standard and custom arrhythmias and alarm limits at the monitoring center.

This application is a continuation in part application of pendinginternational application no. PCT/IB2006/054019, filed Oct. 30, 2006,which claims the benefit of U.S. provisional application Ser. No.60/741,492, filed Nov. 30, 2005.

This invention relates to ECG monitoring systems and, in particular, tothe continuous ECG monitoring of patients in an outpatient setting.

Numerous patients have a demonstrated need for continuous cardiacmonitoring over an extended period of time. This patient populationincludes those who may have arrhythmias such as atrial fibrillation,atrial flutter, and other supraventricular tachycardias, and atrial orventricular ectopy, brady arrhythmias, intermittent bundle branch block,and arrhythmias associated with conditions such as hyperthyroidism orchronic lung disease. Other patients may exhibit symptoms that may bedue to cardiac arrhythmias such as dizziness or lightheadedness,syncope, or dyspnea. Other patients may experience palpitations forwhich it is desirable to correlate patient rhythm with symptoms. Otherpatient conditions may need to be monitored for cardiac effects ofdrugs, in situations where the arrhythmic effects of drugs or theeffects of drugs to suppress arrhythmias should be monitored. For drugswith known arrhythmic effects, possible lengthening of the QT intervalshould be monitored. Patients who have diagnosed sleep disorderedbreathing such as sleep apnea, have suffered a stroke or transientischemia, or are recovering from cardiac surgery may often benefit fromcontinuous cardiac monitoring.

Several monitoring devices are presently used for some of theseconditions. Holter monitors are used to continuously record a patient'sECG waveform over a period of time such as a 24-hour period. However,the data recorded by a Holter monitor is only known and can be analyzedafter the recording period is over. Immediate analysis of the ECG is notpossible when the ECG data is only recorded and not immediatelyreported. Also, many patients feel constrained from engaging in normalactivities when wearing a Holter monitor and its many lead wires andelectrodes, and often object to the discomfort and inconvenience ofthese monitors.

Another monitoring device in present use is the loop or event monitor. Aloop monitor records data in a continuous loop recording. When the loopis full, the loop monitor will overwrite previously recorded data. Aloop monitor is therefore ineffective as a full disclosure recorder foran extended period of time since data can be lost. With an event monitorthe patient is attached to numerous electrodes and wires so that themonitor can be activated by the patient whenever the patient feelssymptomatic. When the patient feels pain or discomfort the patientactivates the monitor to record the ECG at the time of the symptom. Somemonitoring systems also enable the ECG data to be transmitted to a localbase station which relays the ECG data by phone to a diagnostic centerwhere it can be promptly scrutinized for arrhythmias. However thisconstrains the normal daily activities of the patient, as the patientmust continually stay within range of the local base station.

Still other monitors have a recorder which is auto-triggered by acardiac event to record the ECG at the time of the event. The patientwill then connect the monitor to a telephone line modem to transfer theECG data to a monitoring center for review. These systems pose numerousproblems. One is that a patient mistake in connecting the monitor to thetelephone equipment or operating the equipment can result in a loss ofuploaded data. Another problem is that a cardiac event such as syncopecan leave the patient unconscious or disoriented and unable to conductthe upload process correctly or, in some cases, at all. Moreover, if thecardiac event occurs while the patient is traveling in a car,considerable time may pass before the patient returns to the location ofthe uploading equipment and is able to perform the data upload process.

Accordingly it would be desirable for a cardiac monitoring system toovercome the shortcomings of these devices. Such a monitoring systemwould continuously record the patient's ECG waveforms, analyze the ECGfor arrhythmias in real time, and send ECG data to a diagnosingclinician whenever a possibly significant arrhythmia is detected. Thesystem would also be operable by the patient to record a symptomaticevent, preferably with an oral description of the event, and would thenautomatically send the description of the symptom and the associated ECGdata to a clinician or monitoring center for review. The monitoringsystem would desirably be very comfortable and convenient for thepatient to use without disrupting the patient's normal daily activities.

In accordance with the principles of the present invention, an ECGmonitoring system is provided which is completely wireless for patientcomfort and convenience. A small monitor adhesively attaches to thechest of a patient. The monitor continuously analyzes the patient's ECGagainst alarm limits stored in the monitor. If a suspected arrhythmia isdetected, a strip of ECG data is immediately sent to a cellphone andforwarded on to a monitoring center for clinical review. The alarmlimits are downloaded from the monitoring center when the monitor firstmakes contact with the monitoring center and a check is made for updatedconfiguration data each time the monitor contacts the monitoring center.The monitor can be automatically reconfigured with new alarm limitstransmitted from the monitoring center.

In the drawings:

FIG. 1 illustrates a patient wearing an ECG monitoring system of thepresent invention.

FIG. 2 illustrates an electrode patch which adhesively attaches to thechest of a patient and holds an ECG monitor.

FIGS. 3 a and 3 b illustrate front and back views of ECG monitors of thepresent invention which clip into the patch of FIG. 2.

FIG. 4 illustrates how an ECG monitor of FIG. 3 snaps into the electrodepatch of FIG. 2.

FIG. 5 illustrates the cellphone handset of an ECG monitoring system ofthe present invention with its cover.

FIG. 6 illustrates the cellphone handset of FIG. 5 with the coversnapped onto the cellphone.

FIG. 7 is a plan view of the front of the cellphone handset of FIGS. 5and 6 when the handset is in communication with a monitor.

FIGS. 8 a-8 i illustrate some of the screen displays of a typicalcellphone handset of an ECG monitoring system of the present invention.

FIG. 9 illustrates a monitor charging dock and cord for recharging acellphone handset.

FIG. 10 illustrates a monitor inside the charging dock of FIG. 9 priorto closure of the lid of the charging dock.

FIG. 11 illustrates a charging dock of an ECG monitoring system kit ofthe present invention while being used to recharge a monitor and acellphone handset.

FIG. 12 a is a functional block diagram of an ECG monitor constructed inaccordance with the principles of the present invention.

FIG. 12 b is a block diagram of the function of the ECG monitor of FIG.12 a from a hardware perspective.

FIG. 13 is a functional block diagram of a cellphone handset incommunication with a monitoring center.

FIG. 14 is an illustration of the communication between an ECG monitorand a monitoring center and its functions for an ECG monitoring systemof the present invention.

FIG. 15 illustrates a screen display of a setup template for theconfiguration and alert limits of an ECG monitor of the presentinvention.

FIG. 16 illustrates a screen display to set up procedure configurationand alarm limits for an ECG monitor of the present invention, showing acustom alarm.

FIG. 17 illustrates a screen display used to associate the components ofan ECG monitoring kit of the present invention.

FIG. 18 illustrates a screen display used to track the disposition ofECG monitoring kits of the present invention.

FIG. 19 illustrates a screen display used to track ECG monitors andtheir Bluetooth addresses in accordance with the present invention.

FIG. 20 illustrates a screen display used to track ECG monitor usage inaccordance with the principles of the present invention.

FIG. 21 illustrates a screen display used to track cellphone handsets,their phone numbers and Bluetooth addresses in accordance with thepresent invention.

FIG. 22 illustrates a screen display used to track ECG handset usage inaccordance with the present invention.

FIG. 23 illustrates a computerized template used to record suitableelectrode patch placement locations and patch orientations for apatient.

FIG. 24 illustrates a setup screen used to program the generation ofreminders for a patient to recharge a monitor and cellphone handset ofan ECG monitoring system of the present invention.

FIG. 25 illustrates a screen display used by a monitoring center torecord a physician's requirements for reports during use of an ECGmonitoring system of the present invention.

FIG. 26 illustrates a screen display to track account activity duringuse of an ECG monitoring system of the present invention.

FIG. 27 illustrates a screen display of the patient communication logfor an ECG monitoring procedure conducted in accordance with theprinciples of the present invention.

FIG. 28 illustrates a screen display of an ECG viewer used to displaythe data produced by a four channel ECG monitor constructed inaccordance with the principles of the present invention.

FIG. 29 illustrates a screen display of an ECG viewer for an ECG monitorof the present invention with the notification and event windowsexpanded.

FIG. 30 illustrates a screen display of status notifications receivedfrom an ECG monitor of the present invention.

FIG. 31 illustrates a screen display of an ECG viewer with amagnification window for detailed examination of an ECG waveform inaccordance with the principles of the present invention.

FIG. 32 is a flow diagram of a method for setting up an ECG monitoringprocedure in accordance with the present invention.

FIG. 33 is a flow diagram of a method for initially outfitting a patientwith an ECG monitor in accordance with the present invention.

FIG. 34 is a flow diagram of a method for daily replacement and chargingof an ECG monitor in accordance with the present invention.

FIG. 35 is a flow diagram of a method for using the “Call for Help”button of a cellphone handset of an ECG monitoring system of the presentinvention.

FIG. 36 is a flow diagram of a method for using the “Record Voice”button of a cellphone handset of an ECG monitoring system of the presentinvention.

FIG. 37 is a flow diagram of a method for voice contact with a patientto resolve a difficulty reported by an ECG monitoring system of thepresent invention.

FIG. 38 is a flow diagram of activities performed by a refurbishmentcenter in preparing an ECG monitoring system of the present inventionfor use by another patient.

FIG. 1 illustrates the significant patient comfort and ease of use of awireless ECG monitoring system constructed in accordance with theprinciples of the present invention. The man in the drawing of FIG. 1 isgoing about his normal daily activities, unbothered and unhindered bythe continuous ECG monitoring system he is wearing. This is because theECG monitoring system he is wearing is thin, lightweight, andcomfortable to wear. In the main, it is because the ECG monitoringsystem has no wires draped about the man's body. There are no wires fromthe monitor to electrodes on other areas of the body, no wiresconnecting the monitor to a communicator, and no wires connecting acommunicator to a communication network. The ECG monitoring system iscompletely wireless. To a casual observer it would only appear that theman is wearing a cellphone in a carrying case 10 which is circled on thehip of the man. Shown on the chest of the man is a wireless ECG monitor12 of the present invention. Although the location of the ECG monitor 12is shown in FIG. 1, in fact the monitor would be unseen by an observerbecause it would be under the man's shirt. With a diameter of less than2.5″, a thickness of 0.5″, and a weight of less than an ounce, themonitor would be virtually invisible under the man's clothing. As theman goes about his daily activities, the ECG monitor 12 continuouslymonitors, analyzes, and records the ECG of each heartbeat. If anarrhythmia is detected by the monitor, an alert and an ECG strip arewirelessly sent to the cellphone handset in the carrying case 10. Thecellphone handset silently calls a monitoring center which may behundreds or thousands of miles away and relays the alert and ECG stripto the monitoring center. At the monitoring center this cardiacinformation is promptly reviewed by a medical specialist and anynecessary action taken or report made to the patient's physician. Thepatient's cardiac function is monitored in this way for 24 hours a dayfor typically several weeks (e.g., 10-30 days), providing an archive ofECG information and a level of arrhythmia protection not otherwiseavailable on an outpatient basis.

FIG. 2 illustrates an electrode patch 20 suitable for use with awireless ECG monitor of the present invention. This patch and variationsthereof are described in detail in the parent application which ispublished as international publication number WO2007/063436, thecontents of which are incorporated herein by reference. FIG. 2 is a viewof the outward-facing side of the patch 20. The patch is formed of aflexible substrate 22. On the back (patient-facing side) of the patchare four hydrogel electrode pads s1, s2 and s3 and a central electrodepad not visible in this drawing. The central electrode pad is areference or RLD electrode, so named for its correspondence to the“right leg drive” reference electrode of a standard ECG set. The rest ofthe patient-facing side of the patch 20 is covered by a biocompatibleadhesive which securely attaches the patch to the chest of a patient.Electrical signals received at the three electrode pads s1, s2 and s3are coupled to electrical contacts on the outward-facing side of thepatch by a flex circuit layer as described in the parent application andthe signals so provided are used to form three ECG lead vectors asdescribed below. In the center of the patch on the outward-facing sideis a plastic clip 24 with curved lips at the top and bottom into whichan ECG monitor may be snapped and retained as shown in FIG. 4. In thecenter of the clip 24 is a row of elastomeric contacts 26 by which theelectrical signals received by the electrode pads s1, s2 and s3 arecoupled to the ECG monitor, and a reference signal produced by the ECGmonitor is coupled to the RLD electrode for the sensing of looseelectrodes and reduction of common mode noise.

FIG. 3 a is a plan view of the outward-facing front side of an ECGmonitor 30 constructed in accordance with the principles of the presentinvention. The ECG monitor 30 is enclosed in a plastic clamshell casewhich is ultrasonically welded closed or sealed closed with an adhesiveor solvent. On the back 38 of the case as shown in the example of FIG. 3b is a row of electrical contacts 36 which are inserted in and thermallysealed flush with the case surface. In a constructed embodiment thereare three rows of electrical contacts 36. One of these rows makesconnection with the elastomeric contacts 26 of the clip 24 and couplesthe ECG signals into the monitor and applies a small signal to thereference electrode. The other two rows engage matching rows of contactsin a charging dock when the monitor 30 is being recharged as describedbelow. The monitor in this example has no external controls or displaysand no on/off switch, only electrical contacts 36 on the back of thecase. In a constructed embodiment the ECG monitor measures 2.4″ wide by1.9″ high by 0.5″ thick, and weighs 0.9 ounces. Since the case is sealedclosed around its periphery and the contacts on the back are fullysealed, the monitor can be worn in the shower while posing no hazard toeither the patient or the monitor. As the case is closed permanently inthis embodiment, replacement of the internal battery or components isnot possible in this design. If the monitor fails to operate properly orthe battery is no longer capable of holding a sufficient charge, it isdisposed of properly.

The plastic case is keyed on the bottom with an indentation 32 thatmatches the shape of the bottom of the clip 24 of the electrode patch20. A notch 34 is also formed in the bottom of the case, which matches aprojection inside the bottom of the clip. The example of FIG. 3 b hastwo indentations 34 a and 34 b for keying to matching projections of apatch clip 24. This keying mandates that the ECG monitor 30 can only besnapped into the clip 24 in one orientation. FIG. 4 is a side viewshowing the monitor 30 being snapped into the clip 24. The bottom of themonitor of FIG. 3 a is inserted into the clip first with the keying32,34 of the bottom of the monitor engaging the matching shape of thebottom of the clip. The top of the monitor is then tilted back to thetop of the clip as indicated by the arrow in FIG. 4, and the top of themonitor snaps under the top 28 of the clip 24. As the monitor snaps intoplace, providing a tactile indication to the patient that the monitor isin place, the contacts 36 on the back of the monitor are aligned withand engage the row of contacts 26 of the clip. The monitor is now inposition to monitor the ECG signals of the patient, which commences atonce as the monitor senses this engagement, terminates its “sleep” mode,and powers up to full operational capability.

FIGS. 5-7 illustrate a cellphone handset 50 suitable for use with theECG monitor 30 of FIG. 3. The cellphone handset 50 includes a standardcommercially available “smart phone” cellphone 52 over which is placed aplastic cover 56, which snaps into place. The cover 56 functions tocover up most of the keys of a standard cellphone and restricts thepatient to use of only a few buttons necessary for the ECG monitoringprocedure. The cover thereby turns an often complex commercial cellphoneinto a communicator which is simple for the patient to understand anduse. FIG. 5 shows the cellphone 52 being placed in the cover 56. Theon/off button 54 is shown located on the side of the cellphone 52 andthe cellphone 52 is turned on before the cover is snapped on. As FIG. 6,shows, the cover 56 has a hole on the front the size of the cellphonescreen so that the screen 58 of the cellphone 52 can be observed throughthe hole in the cover. The cover also has two partial cutouts 62 and 64on the front. These cutouts 62,64 can be depressed by the patient asbuttons to operate the two underlying keys of the cellphone keypad. Inother implementations the cover may cover most of the keys of thecellphone and leave only a few keys uncovered and available for use. Thecutouts or uncovered keys are operated as “soft keys”, with thefunctions affected by key depression at any moment shown on thecellphone screen 58 at the bottom of the screen and just above eachcutout. Depending on the operation of the monitoring system and theactions of the patient, these functions will change as described below.FIG. 7 is a front view of the covered cellphone handset showing thescreen 58, the buttons below the screen, a small hole 72 at the top ofthe cover through which the patient can listen to the earphone of thecellphone, and three small holes 74 at the bottom of the cover 56, intowhich the patient can speak when recording a message or conversing withthe monitoring center as discussed below. When the cellphone 52 isturned on and the cover 56 is in place, there are only two buttons, 62and 64, which can be operated by the patient in this embodiment.

A significant advantage of this commercial cellphone with coverimplementation is that the monitoring system can be quickly andinexpensively adapted to new cellphone technology. As new cellphonemodels are introduced and older ones become obsolete, a new cellphonemodel can be used by redesigning the cover to fit the new model andproducing the new cover in inexpensive high volumes as an injectionmolded part, for instance. The effort and cost to do so is far less thanthat required to design and produce a custom cellphone communicator,which would not keep up with technological changes and would beexpensive in low volumes. The inventive approach of adapting a new coverto new commercial cellphone models enables the monitoring systemdesigner to take advantage of the low cost of high volume commercialcellphones and avoid the need for an expensive and technically limitingcustom communicator.

In other embodiments it may desirable to provide additional buttons orbutton functions for the patient to use. For instance, an informationbutton labeled “i” can be provided for use by a patient when he has aquestion about the current state of the monitor or a message. If amessage appears on the screen which the patient does not understand, thepatient presses the “i” button, and the cellphone handset will provideinformation about the current state of the monitor or message on thedisplay 58. Such information is context driven as determined by thecurrent state or status of the system. The information can be providedas text on the display 58 of the handset, or as a voice prompt which isplayed and articulates the information audibly. Another button which maybe desirable is a “911” button which calls the 911 emergency responseservice when pressed. Another button which may be useful in a particularembodiment is a “Physician” button which automatically dials the phonenumber of the patient's physician when pressed.

FIGS. 8 a-8 i are examples of displays shown on the screen of thecellphone handset during use of the ECG monitoring system of the presentinvention. FIG. 8 a shows the screen display when the monitor andhandset are in the “ECG streaming” mode. This is a mode which can beinitiated by the physician when the patient is first set up with themonitor. During setup, the physician will place the electrode patch andmonitor at various locations on the patient's chest, looking for anumber of locations where a good ECG signal can be received. In aconstructed embodiment this is done by peeling a portion of the releaseliner to uncover the electrode gel without uncovering the patch adhesiveas explained in international patent application number IB2007/054879(Cross et al.) In order to gauge the effectiveness of a given location,the physician will type in a certain key combination on the cellphonekeypad when the cover 56 is removed from the cellphone. The keycombination switches the cellphone operation to the ECG streaming mode.If the ECG monitor and electrode patch are not both attached to thepatient at the time this mode is entered, the screen display of FIG. 8 ais shown, with the instruction to connect the monitor to the patient.When the monitor 30 is in place on the patient, the patient's ECGwaveform is streamed to the display and shown in real time as a functionof time and amplitude as it is received from the patient, as shown inFIG. 8 b. The ECG monitor sends four channels of data to the monitoringcenter, three channels of ECG lead data identified in FIGS. 8 b as c1,c2, and c3, and a channel M of motion information. In other embodimentsother channels of data may be provided such as a reference signalchannel. By depressing the right button 64 the physician can togglethrough the display of all four channels of information. After thephysician has found the desired number of electrode patch locations andhas verified operation of the ECG monitor 30 and cellphone handset 50 inthe ECG streaming mode, the left button 62 is depressed to exit the ECGstreaming mode. The “System OK” display of FIG. 8 c should then appearon the screen. This screen appears when the following conditions aremet: the ECG monitor 30 is communicating with the cellphone handset 50;the ECG monitor and handset system software are both functioningproperly; the contact quality of the electrode patch 20 to the skin ofthe patient is acceptable; and the most recently conducted monitorself-test was successful. Thus, the display of FIG. 8 c indicates thatthe ECG monitor 30 and patch 20 are properly applied to the patient andthat the ECG monitor and the cellphone handset 50 are operatingproperly. In other implementations it may be desirable to display amessage or graphic indicating that communication with the ECG monitor issatisfactory. Another alternative is for the cellphone handset toselectively produce a tone when communication with the monitor issatisfactory, such as a beep in synchronism with received R-waveinformation. At the bottom of the display of FIG. 8 c are the buttonlabels seen on the screen above buttons 62 and 64 when the system is inits normal monitoring operation. The left button 62 is used to “RecordVoice”, and the right button 64 is used to “Call For Help.”

FIG. 8 d shows a reminder display, reminding a patient at the end of theday that the monitor and handset need to be charged. As described below,this reminder screen will appear at a pre-programmed time each day ifthe patient has not begun to recharge the monitor and handset. FIG. 8 eis a display which appears when the battery charge of the cellphonehandset is detected to be low. FIG. 8 f is a display that notifies thepatient that the battery charge of the monitor 30 is low. FIG. 8 g is adisplay that appears on the handset screen when the cellphone handset 50loses communication with the ECG monitor 30. In the constructedembodiment the ECG monitor 30 and the cellphone handset 50 communicatewith each other via wireless Bluetooth radio. The patient is advised tokeep the cellphone handset and ECG monitor within six feet of each otherto maintain the Bluetooth wireless link. If the patient sets the handsetdown and walks away from it, the display of FIG. 8 g will appear whenBluetooth communication is broken. It is for this reason that thepatient is advised to wear the cellphone handset in a carrying case onthe waist, which maintains the Bluetooth link continuously. FIG. 8 h isthe display shown on the screen when the ECG monitor 30 detects poorcontact with the skin of the patient. The patient is advised to pressdown on the edges of the electrode patch 20 to more securely adhere itto the skin.

For all of these alert conditions, the patient can depress the leftbutton 62 to dismiss the alert from the screen (FIG. 8 d). Depressingthe right button 64 will cause the reminder to reappear in an hour.Alerts which have been dismissed will remain displayed on the screen assmall icons as shown in FIG. 8 i, until the patient takes the requestedaction or addresses the notified condition.

Whenever an alert appears on the screen, the cellphone handsetconcurrently sounds a tone to audibly inform the patient that anotification has appeared. The attention of the patient is therebydirected to the notification. Simultaneously with or instead of thedisplay notifications, voice prompts stored on the cellphone handset canbe played through the speakerphone of the handset. For example, insteadof or in addition to a display showing “Poor Contact” and “Press down onedges of patch,” the patient can hear a voice saying that the contactbetween the patch and the body has become poor and the patient shouldpress down in the center of the patch and around its edges to reattachthe patch to the body properly.

A kit of the present invention also comes with a charging dock 90 asshown in FIG. 9 to recharge the ECG monitor 30 and the cellphone handset50. FIG. 9 shows a charging dock of a constructed embodiment of thepresent invention, which includes a base unit 100 as shown in FIG. 10with a hinged cover 102 for charging the monitor 30 and a cable 92 witha plug 94 for charging the handset 50. The a.c. power cord is notvisible in these drawings. The monitor 30 is placed in its form-fittingspace inside the base unit 100 as shown in FIG. 10 with its electricalcontacts 36 facing downward. The space is keyed so that the monitor willonly fit in the space when an LED 104 is positioned in the notch 34 ofthe monitor. With the lid 102 open as shown in the drawing, the monitorrests lightly on elastomeric charging contacts underneath the monitor.In other embodiments the contacts may be spring-loaded pins. The lid 102must be closed for charging to begin; charging will not take place withthe lid open. When the lid is closed the inside of the lid presses themonitor firmly against the charging contacts. This engagement ismeasured by the charging dock, which measures the impedance of thecontact engagement. With the lid closed as indicated by the arrow inFIG. 10, the circuitry and software program inside the base unit 100start to initialize and the LED begins to blink with an orange color.After initialization is complete, the charging circuitry begins tocharge the lithium-ion battery inside the monitor 30 and the LED 104emits a steady green light. As the monitor is being charged, the monitorbegins wirelessly transmitting its archive of ECG data to the cellphonehandset 50. The cellphone handset immediately relays the ECG data on tothe monitoring center for analysis, reporting and storage. Aftersuccessful receipt of the archive data has been acknowledged by themonitoring center, the ECG data in the monitor is erased or cleared frommemory for receipt of new ECG data when the monitor is reattached to thepatient.

While the monitor 30 is being charged the cellphone handset 50 can becharged at the same time as shown in FIG. 11. The plug 94 of cable 92 isconnected to the cellphone handset and the charging dock charges thecellphone handset at the same time as the monitor is being charged. Inother embodiments the cellphone handset is recharged using a standardcellphone charger supplied by the cellphone manufacturer. As thecellphone handset is being charged a light 96 is illuminated on thehandset to indicate that charging is taking place.

After the monitor 30 has been recharged and its archive data transferredto the cellphone handset from the charging dock, the circuitry andsoftware of the monitor run a self-test of the monitor 30. Among theelements of the monitor which are tested are the random access memory ofthe monitor, reading and writing to the monitor flash card is tested,the motion channel of the monitor is tested, the wireless radio of themonitor is tested, and the analog and digital power supplies of themonitor are tested. A charging dock can also produce test signals whichare applied to the electrode contacts of the monitor for testing the ECGcircuitry of the monitor. If charging is not successful, thetransmission of the archive data is not successful, or any of theself-tests is not successful, the illuminated LED begins to alternatelyflash orange and green to indicate that an error condition is present,and to inform the patient that a service call should be made to themonitoring center.

FIGS. 12 a and 12 b illustrate the functions and components of an ECGmonitor constructed in accordance with the principles of the presentinvention, FIG. 12 a from a functional perspective and FIG. 12 b from ahardware perspective. The ECG electrodes s1, s2, s3 and RLD of the patch20 are coupled to ECG front end circuitry 202. The ECG circuitry 202amplifies and filters the ECG signals received from the body of thepatient and injects a small signal to the RLD electrode to detect looseelectrodes. Suitable ECG front end circuitry is described ininternational application number IB2007/054461 (Herleikson), filed Nov.2, 2007, which is incorporated herein. A small 75 Hz signal is injectedinto the body from the RLD electrode and can be sensed at each of thes1, s2, and s3 electrodes. The signal received at each of the s1, s2,and s3 electrodes is applied to an input of a respective differentialamplifier, along with a reference voltage formed by combining signalsfrom the s1, s2, and s3 electrodes. If an electrode becomes loose on thebody, the 75 Hz signal will be detectable at the output of thedifferential amplifier of that electrode. When the electrodes areproperly in contact with the patient the signal will disappear as acommon mode signal. A signal from the combination of the electrodesignals is fed back to the RLD electrode as a feedback signal to balancecommon mode voltage and noise. The analog signals from the s1, s2, ands3 electrodes are converted to digital signals by A/D converters 204 bysampling at a 300 Hz rate. This sampling frequency is a multiple of the75 Hz loose lead signal, enabling the 75 Hz signal to be easily filteredout. The digitized electrode signals are coupled to a lead signalformatter 206 which forms multi-vector lead signals s1-s2 and s1-s3.These two signals can be combined to compute a third vector, s2-s3. Thethree lead signals are formed in a manner equivalent to the manner inwhich the I, II, and III leads of a conventional ECG lead set areformed. The lead signals are coupled to an ECG characteristic analyzer208 which defines characteristics of an ECG signal such as the QRScomplex, the average beat, R-R interval and pulse rate. A suitable leadsignal formatter and ECG characteristic analyzer are described in U.S.provisional patent application No. 60/954,367 (Zhou et al.), filed Aug.7, 2007. The ECG characteristics are coupled to an arrhythmia detector210 which analyzes the ECG for certain signal characteristics andthreshold levels determined by the patient's physician and coupled tothe arrhythmia detector, as described in detail below. If a sought-afterarrhythmia is detected, that event is coupled to the transmit/receivecontroller 218, along with a 90-second ECG strip from 60 seconds priorto the occurrence of the event to 30 seconds after. The time of theevent is marked in either the event information, the ECG strip, or both,and can be indicated as the time the event first appears in the ECGdata, the time the event ends, the time the event was detected, or someother clinically significant time mark. The ECG strip and eventinformation, which may be sent separately or merged together, arepacketized and transmitted to the cellphone handset by a Bluetooth radio220. This information and all of the ECG data received by the monitorare downsampled to a 200 Hz reporting rate and stored on a 2 GB flashcard memory 216. A 2 GB memory can hold approximately 36 hours of ECGdata at this reporting rate.

Located inside the monitor 30 is a motion detector M such as anaccelerometer or a piezoelectric strip. The motion detector sensesmotion of the monitor while attached to the patient and hence motionalactivity of the patient. The motion signal from the detector isamplified, digitized by an A/D converter 214, and stored on the memory216. The motion signal is a fourth data channel sent to the monitoringcenter along with the s1, s2, and RLD ECG signals and can be correlatedwith the ECG information to interpret possible patient conditions asdescribed in international patent application publication no.WO2007/066270 (Solosko et al.) For instance, a pause in the ECG signalaccompanied by a large motion signal could indicate that a patient withsyncope has fainted.

The monitor also includes power management circuitry 232 which monitorsthe condition of the lithium-ion battery 230 and controls charging ofthe battery. A fuel gauge 235 monitors charge into and out of thebattery and continually assesses the state of the battery, its chargelevel, and its capacity for recharging.

Since the monitor 30 is permanently sealed in this example with noexternal controls, there is no ability or need to turn the monitor onand off manually. As soon as the monitor is fully assembled in thefactory, it begins operating immediately. However, if the monitor doesnot sense after a predetermined period of time that its contacts areengaged with contacts of a charging dock or a patch, the powermanagement system of the monitor switches the monitor into a “sleep”mode. In the sleep mode the only circuitry kept operating is that whichsenses engagement with the contacts of a charging dock or patch, whichconsumes only a small amount of current. When the power managementsystem senses this engagement, the monitor is turned on to its fullyoperational state. Thus, the monitor can remain idle in inventory forweeks or months and awake virtually fully charged when placed intoservice.

In a constructed embodiment the core of the monitor is a microcontroller240 which receives the digitized ECG and motion signals and performs thelead signal formatting, analysis, and arrhythmia detection describedabove, as well as the transmission and receipt of data by the Bluetoothradio 220. The microcontroller also has a USB port which is coupled tothe row of contacts on the back of the monitor case, enabling data andprograms to be coupled to the microcontroller and its data storagedevices 216 and 244.

FIG. 13 shows the balance of a monitoring system of the presentinvention, including a block diagram of the cellphone handset 50 and acommunication link to a monitoring center 400. The cellphone handset 50is a commercially available cellphone with a Windows Mobile operatingsystem for a smart phone. The cellphone includes cellphone electronicswhich receives inputs from a keypad 302 and displays graphicalinformation on a display 58. The cellphone handset 50 includes aBluetooth radio 310 which communicates with one or more monitors 30. A 2GB memory 304 stores programs and data such as ECG data transferred tothe handset from an ECG monitor. The cellphone handset is powered by abattery 314 controlled and charged by power management circuitry 312.The Windows Mobile operating system enables the cellphone directorystructure to be viewed by a personal computer when the cellphone isconnected to the p.c. by the same (USB) cord 92 used to charge thebattery 314. An executable program which controls the cellphone tooperate as described herein is loaded into a memory of the cellphone,either memory 304 or the cellphone's built-in memory, along withgraphics for the cellphone display as an installer routine. The startupdirectory of the operating system is modified with a link to theexecutable program so that, when the cellphone is turned on and bootsup, it will automatically begin running the executable program anddisplaying the graphics designed for the monitoring application. Thecellphone handset 50 communicates over a cellular network and then landlines to a monitoring center 400 which receives ECG data and statusnotifications from the ECG monitor and sends commands and configurationinformation to the monitor.

The interaction of monitoring components of the present invention whichare with the patient and those that are at the monitoring center isshown in FIG. 14. The monitor communicates by Bluetooth (BT) with thecellphone handset 50. The ECG information is sent in an HTTP protocol toa server 402 at the monitoring center 400. If the transmission is at thetime of an event, the accompanying ECG strip is viewed by an ECGtechnician on an ECG viewer 404. If the transmission is a daily archiveof ECG data, it is sent to a Holter 2010 system 406 for triage andreporting. Reports from an event diagnosed by an ECG technician or dailyreporting of an archive are forwarded to an onsite patient administratoror the administrator in charge of the patient and study. Overallcoordination of the monitoring center is directed by one or moremonitoring center administrators.

The transfer each day of a complete recording archive of full disclosuredata, every heartbeat of the patient, enables subtle cardiac conditionsto be diagnosed which may not be found with typical ECG strip reporting.For instance, a high heart rate alarm limit may be set to a levelconsiderably above the patient's normal heart rhythm. Thus, a slightincrease in the patient's heart rate may not be detected as a reportableevent by the patient's arrhythmia detector. However, the slight increasein heart rate may recur numerous times in a short period of time, or mayextend continuously over a long period of time. These more subtlebehaviors of cardiac rhythm can be recognized by more sophisticatedanalysis systems operating on full disclosure data such as the Holter2010 system mentioned above. The Holter 2010 system can be used toanalyze each daily archive of data and produce a daily report whichidentifies such symptomatic patterns of heart rhythm. The identificationof such subtleties in the daily archive by sophisticated analysisprograms at the monitoring center can lead to a prompt diagnosis of thepatient's condition or to the resetting of alarms and alarm limits tomore effectively reveal characteristics of a cardiac condition.

A patient administrator such as the patient's physician may decideduring a study to change the parameters of an arrhythmia which is to bedetected. For example, the threshold for a detected tachycardia may bereset to 160 bpm. Such a change may be instituted by an ECG technicianat the monitoring center, and the new setup sent to the patient'smonitor as a configuration change. The new configuration information isdispatched by the server 402, received over the cellphone network by thecellphone handset, then forwarded over the Bluetooth link to the monitor30, where it is installed in the arrhythmia detector.

FIG. 15 illustrates a setup screen which may be used to set up or resetthresholds for arrhythmia detection by the ECG monitor 30. In thisexample limits can be set from pulldown boxes for ventricularfibrillation, high heart rate, low heart rate, very low heart rate,asystole, pause in the heartbeat, and atrial fibrillation. In additionto detection limits, the user can also set a priority for an alert, suchas urgent, medium, or low priority. When the ECG technician has set thedesired thresholds and priorities, the configuration is saved with the“Save” button at the bottom of the screen. If the study has not yetstarted, the configuration information is stored on the server 402 atthe monitoring center and uploaded to the monitor when the monitor isinitially attached to the patient and its communication links areestablished. On the monitor's first communication with the monitoringcenter the monitor checks for configuration information, which is thenuploaded and installed in the arrhythmia detector. If the study isalready underway, the new configuration is immediately uploaded forinstallation on the monitor.

In addition to the seven standard arrhythmia alarms shown in FIG. 15,the user also has the opportunity to set a custom alarm for a particularpatient. The box 160 at the bottom of the configuration screen of FIG.16 contains a custom alarm which has been enabled for the illustratedconfiguration. The box 160 gives an example of some of the parameterswhich may be configured for a custom alarm setting.

A monitoring system of the present invention is typically supplied as akit of all of the components needed for a monitoring procedure. FIG. 17illustrates a screen by which a monitoring or refurbishment center mayassemble an ECG monitoring kit of the present invention from aninventory of ECG monitors 30 and cellphone handsets 50. A box 172 at thetop of the screen displays a list of monitors 30 in inventory. Anoperator clicks on a monitor to highlight it, then clicks on the “AddSelected Monitor” button to add the selected monitor to the kit.Similarly, the operator can highlight a cellphone handset communicatorin box 174 and click the “Add Selected Communicator” button to add aparticular cellphone handset to the kit. The serial number of the kitbeing assembled appears in box 176 with the serial numbers of themonitors and cellphone handset shown below. When the operator issatisfied with the assembled kit, the “Create Kit” button at the bottomof the screen is clicked to assign the selected components to aparticular monitoring kit.

FIG. 18 shows a screen by which an operator can track monitoring kits asthey are sent to and received back from physicians, hospitals, andclinics. At the top of the screen are boxes by which an operator cansearch for a particular kit by entering the serial number for the kit inbox 182, then clicking the “Search” button. Similarly the operator canpick another parameter against which to search for a particular kit. Forinstance, the operator can select a location to which a kit has beenshipped in box 184, then search for all kits shipped to that location.The large box 186 at the bottom of the screen shows shipping informationconcerning a number of kits, including the date the kit was shipped to auser, the location of the user, and the serial numbers of the monitorand handset components of the kit. When a kit has been received by therefurbishment center as discussed below, the “Received Date” can beentered for the kit. The tabs at the top of the box 186 are used to markparticular kits as shipped or received.

FIG. 19 shows a screen by which an operator can track serial numbers andBluetooth addresses for monitors and can pair a selected monitor with aBluetooth address of a cellphone handset. Using the boxes at the top ofthe screen, the operator can enter a serial number to search for aparticular monitor. The large box 196 at the bottom of the screen listsall of the monitors in inventory and their serial numbers and Bluetoothaddresses. New monitors can be added to the inventory by entering theircharacteristic information in the small boxes at the bottom of thescreen. FIG. 20 is a screen by which an operator can search forindividual monitors by serial number, shipping dates, and by thelocations to and from which they have been shipped. This screen alsoenables a search of monitors which have been received back from a userafter a study is complete. The large box 250 at the bottom of the screenlists the search results of monitors by their kit serial numbers, datesthey were shipped to a location, and the dates the monitors werereceived back from those locations.

FIG. 21 shows a screen by which an operator can search for cellphonehandsets by serial number, Bluetooth address, or phone number. The largebox 252 at the bottom of the screen lists the search results forcellphone handsets and their identifying numbers, and enables newhandsets to be added from the small boxes at the bottom of the screen.

The screen of FIG. 22 is similar to the monitor screen of FIG. 20 andallows cellphone handsets to be searched and listed by shipping locationand kit serial number. This screen also enables tracking of cellphonehandsets as they are returned from a user.

When a physician or nurse is outfitting a patient with a monitoring kitfor a study, one of the first tasks is to find locations on thepatient's chest where the patch can be applied so that the attachedmonitor will receive a strong ECG signal. Furthermore, it is desirableto find a number of acceptable locations so that one location on thechest is not used repeatedly, potentially causing skin irritation fromrepeated use. FIG. 23 shows an interactive screen by which the nurse orphysician can record information concerning patch placement. At the topof the screen is data concerning the procedure or study, such as startdate and end date of the procedure. The screen can also record the dateson which the patch positions were updated and who updated theinformation. The body template of figurine 260 at the bottom of thescreen shows three patches over the left side of the chest. These patchgraphics can be dragged to different positions on the torso template,rotated if required, and then dropped to record an acceptable chestlocation for attachment. A suitable location on the patient's chest maybe found by clipping a monitor into a patch and peeling away the portionof the release liner of the patch which covers the electrode locations,as described in U.S. provisional patent application No. 60/869,009(Cross et al.), filed Dec. 7, 2006. The patch can then be placed andrepositioned to multiple chest locations with the hydrogel of theelectrodes conducting ECG signals to the monitor. Alternatively asdescribed in the Cross et al. patent application, if the release linerhas conductive coverings over the electrode locations, the patch andmonitor can be maneuvered to find suitable locations without peelingaway the release liner. Each time a suitable location is found, a patchgraphic 264 is repositioned over the body template 260 to mark theidentified location. The screen of FIG. 23 can be saved and referred toeach time a new patch is to be applied by the nurse or physician duringthe study, or a printed copy taken home by the patient and referred toeach time it is necessary to replace a patch. Alternatively oradditionally an electronic copy of the body template can be displayed onthe cellphone handset display 58 to guide the patient when replacing apatch. Patches can normally be worn for about three days before theyneed to be replaced.

FIG. 24 shows a screen which is used to record information about aprocedure including the time each day when a patient is to be remindedto recharge the monitor and the cellphone handset. This screen isnormally filled in when the monitoring kit is first given to the patientand the patient decides when he or she is going to recharge the monitorand handset. In a typical procedure the patient will wear the monitorand the handset all day as the patient goes about his or her normaldaily activities. At the end of the day when the patient retires for thenight is a convenient time to recharge the monitor and the cellphone.The patient will take a recharged monitor from the charging dock 90,remove the monitor in use from the patch and place it in the chargingdock, and snap the freshly charged monitor into the patch. Just beforegetting into bed the patient will attach the cellphone handset to thecord 92 of the charging dock. The used monitor and the cellphone canthen recharge during the night. The cellphone is left on at all times,and the charging dock is preferably left on a bedside table so that thecharging cellphone handset will remain in range for Bluetoothcommunication with the monitor on the patch as the patient sleeps. Whilethe patient sleeps the used monitor is recharged, its archive data sentto the cellphone and on to the monitoring center, the monitor self-testsperformed, and the previous day's archive data cleared from memory inpreparation for the next daily use of the monitor. It is preferable forthe kit to include two monitors so that one can be worn for monitoringwhile the other is being recharged and its archive data transmitted tothe monitoring center. Typically, the patient will retire for the nightwearing the freshly charged monitor while the used monitor is in thecharging dock being recharged during the night and transmitting itsarchive of ECG data to the cellphone handset and on to the monitoringcenter. If the patient experiences a detected arrhythmia during thenight, the event notification and ECG strip are sent to the cellphonehandset by the Bluetooth link and immediately sent on to the monitoringcenter by the handset. Both monitors, the one being worn by the patientand the one in the charging dock, are in Bluetooth communication withthe cellphone handset at this time and events detected by the monitorbeing worn by the patient are immediately sent to the monitoring centerwithout waiting for completion of the archive data transfer, either on apriority interrupt or time-interleaved basis.

If the patient forgets to place the monitor in the charging dock so thatits archive data can be uploaded to the monitoring center or isotherwise unable to do so, the patient will be prompted by the cellphonehandset to do so, as shown in FIG. 8 d. If the patient dismisses theprompt or ignores the prompt and continues to wear the monitor, theremay come a time when the memory of the monitor has been completelyfilled with recorded ECG data. In this situation the monitor will beginto operate as a loop recorder. Newly acquired ECG signal data will bestored in the memory and the oldest stored ECG data in the memory willbe overwritten and lost.

When the patient gives the physician or nurse a schedule of the timeeach day when the patient expects to start the recharging procedure, thetime for each day is recorded on the screen of FIG. 24. A printed copyof the screen may then be given to the patient to take home. Inaddition, the screen is forwarded to the monitoring center and thecharging reminder times sent as configuration information to thepatient's monitor or handset. At the appointed time each day, a rechargereminder message will appear on the screen 58 of the handset (see FIG. 8d), accompanied by a tone or voice prompt to draw the attention of thepatient to the reminder. The schedule can be easily changed by sendingdifferent reminder configuration information to the monitor or handset.

FIG. 25 shows a screen by which the reporting requirements of thephysician can be recorded by the monitoring center. This screen showsthe procedure start and end dates at the top of the screen. On the“Reports deliver” section of the screen are listed the time when a dailyreport will be sent to the physician and the mode by which it will besent. Generally, the physician will receive a report each day of theprevious day's events and an analysis of the previous day's 24 hours ofECG information from the daily ECG archive of data. This example alsoshows the time and date when the reports delivery section was updated.

Reports and patient information may be posted on the server 402 at themonitoring center for access by particular accounts. An account may bean individual physician, hospital, or clinic. Patient information mustbe password-protected for the security of individual patient data. FIG.26 illustrates a screen by which the monitoring center may trackactivity of a particular account. The top of the screen gives statusinformation and information about the account's password and its use. Ahigh number of failed attempts to gain password access may be anindicator of someone seeking unauthorized access to the accountinformation, which needs to be investigated. Login activity for theaccount is also tracked on this screen. The list in box 262 at thebottom of the screen shows individual sessions when the account loggedonto and out of the server including the time of the session.

FIG. 27 is a screen showing a patient communication log with themonitoring center. The search boxes at the top enable an operator tosearch for patient information by site, physician, or patient. Thesearch results, showing patients, their physicians, their procedures,and the procedure dates are returned in box 272. Detail for a selectedpatient is shown in box 274. The most recent communication between thepatient and the monitoring center is recorded at the top of the box, andearlier communications are listed at the bottom of the box.

FIG. 28 illustrates an ECG viewer screen suitable for receiving andanalyzing event information received at the monitoring center from anECG monitor of the present invention. In this embodiment the ECG viewerscreen has three major sections: a Notification window 282 which showsinformation about a particular procedure or study and lists thenotifications received from that patient; an Events window 284 whichdisplays the information received at the time of an event; and an ECGviewing window 286 in which the data received over the channelstransmitted by the monitor may be analyzed in detail. In FIG. 28 theNotification and Events windows are unexpanded and the ECG viewingwindow is expanded. In this embodiment the ECG monitor 30 transmits fivechannels of data and the cellphone handset transmits a voice channelrecorded with the handset. The data channels are three ECG signals, s1,s2, and s3 in this example, the RLD signal (“rld”), and the motionchannel (“vp”). Differential lead signals s1-s2, s2-s3, and s1-s3 may bederived from the ECG signals of this example. The RLD signal may be usedto further process and refine the lead signals and identify noiseconditions. The controls at the left of each display strip allow anoperator to adjust the scaling and other parameters of the stripdisplay. In the display strips of this example it is seen that asignificant motion signal has occurred at the time of the sizeable ECGsignals of the s1-s2 and s1-s3 channels. The audio controls 288 at thebottom of the display enable a transmitted voice recording from apatient to be replayed by the ECG viewer operator.

FIG. 29 illustrates the ECG viewer screen of FIG. 28 with theNotification window 282 and the Events window 284 expanded. In aconstructed embodiment the monitor 30 sends a notification every timethe status of the monitor changes and these notifications, as well asthose originating from status changes of the cellphone handset, areforwarded on to the monitoring center by the cellphone handset. Forexample, when the monitor senses that it is attached to a patient andreceiving ECG signals from the patient, a status message is sent to themonitoring center. When the monitor detects a loose lead, a statusmessage is sent to the monitoring center. When the loose lead isreattached a status message is sent to the monitoring center. When themonitor is removed from the patch a status message is sent to themonitoring center. Thus, the continual flow of status messages enablesthe monitoring center to evaluate the patient's use of the monitor andthe technician at the monitoring center can intervene with a call to thepatient's cellphone handset if the flow of messages indicates that thepatient is having a problem or overlooking something. Table 1 belowlists some of the typical messages which may be sent during use of amonitoring system.

TABLE 1 Notification Type Monitor on patient, operating properly StatusLoose lead Status Loose lead corrected Status Monitor removed frompatient Status Monitor powered down Status Low battery (monitor) StatusLow battery (handset) Status ECG streaming mode Status Bluetoothcommunication lost Status Bluetooth communication restored StatusCellphone communication lost Status Cellphone communication restoredStatus Self-test successful Status Self-test unsuccessful Alert Monitorplaced in charging dock Status Monitor removed from charging dock StatusMonitor charging started Status Monitor charging completed StatusMonitor charging unsuccessful Alert Cellphone charging started StatusCellphone charging completed Status Cellphone charging unsuccessfulAlert Charging dock error Alert ECG archive transmission start StatusECG archive transmission complete Status Event information + ECG striptransmitted Alert: priority = hi, med, low Voice message + ECG striptransmitted Alert: priority = hi, med, lowDifferent notifications can be handled in different ways. For example,interruption of Bluetooth communication may be a common occurrence. Apatient may set the cellphone handset down and walk away to perform sometask, resulting in a loss of Bluetooth communication when the monitor isout of range with the cellphone handset. A few minutes later the patientreturns to the cellphone handset and picks it up and puts it back in thecarrying case, a purse or pocket, which re-establishes the Bluetoothcommunication when the monitor and cellphone handset are back withinBluetooth signal range of each other. In such circumstances it may bedesirable to delay notification of Bluetooth communication loss for fiveor ten minutes to allow a period of time for communication to berestored before sending a notification. Alternately, the communicationloss notification may be sent immediately as a status message, and if anotification that communication has been restored is received shortlythereafter, the notification canceled or automatically marked asresolved. If the resolution notification is not received within five orten minutes or some other predetermined period of time, the priority ofthe notification is raised at the monitoring center to bring it to theattention of a technician. Loose lead notifications may similarly bedelayed or subject to priority escalation to allow the patient torecognize and correct the situation without a notification being sent orresponded to by the monitoring center.

It will be appreciated that different status notifications can originatefrom different sources. A notification that Bluetooth communication hasbeen lost must originate from the cellphone handset since the monitor isout of communication with the handset at this time and cannot originatethe message. Similarly a notification that cellphone communication hasbeen lost will originate at the monitoring center, generally when themonitoring center tries to send a message to the cellphone and findsthat it is unable to do so.

In the example of FIG. 29 all notifications received from the patientare listed in the Notifications box 282. Routine status notificationsappear in normal text and in chronological order of receipt. Higherpriority alerts are displayed at the top of the list of notificationsand are color-coded to indicate urgency, for example, yellowhighlighting for medium priority alerts and red highlighting for highpriority alerts. In a preferred embodiment, ventricular fibrillation andasystole events are of the highest priority, heartbeat pauses and heartrate notifications are next in priority, loose lead and poor electrodecontact notifications are lower in priority, and other status changesand technical alerts such as low battery and loss of communication areof the lowest priority. As the notifications are reviewed by an ECGtechnician at the monitoring center they may be processed appropriatelythen deleted from the displayed list. The second box 283 in theNotification window 282 has entry spaces where the technician can entera disposition for the notification and provide appropriate comments withthe disposition. The Notification window thereby provides a task listwhich the technician can use to review and handle notifications from apatient's monitor in a priority order and efficient manner. In aconstructed embodiment multiple technicians may view the notificationsfrom the same patient at the same time, but when a technician hasselected a particular notification to analyze and disposition, the otherECG viewers are locked out from selection of the notification so thatonly one technician can work on disposition of a notification at anygiven time. This prevents redundant processing of a single notificationand enables flexibility in the operation of multiple ECG viewers at alarge monitoring center.

The status notifications can also be displayed on a separate screen asshown by the screen display of FIG. 30. As this example illustrates, lowpriority mode change status notifications are listed below the higherpriority event “alarm HRLo” at the top of the list. Notifications whichhave been dispositioned by a technician are marked by a check mark inthe box at the left side of a notification. The boxes at the top of thescreen are used to search for notifications of certain characteristics,such as Event notifications or notifications received during a selectedtime period.

When an Event notification is received, including a patient voicerecording, the Event notification is accompanied by a 90-second ECGstrip which was recorded starting sixty seconds prior to the event timeand continuing for thirty seconds thereafter. Event notifications willappear in the Event window 284. The identity of the event is displayedin the first box 285 and the ECG strip transmitted with the eventnotification appears in box 287. The ECG technician can thereby quicklyreview the ECG signal from the time of the event. If more detailedanalysis is desired, the ECG strip can be reviewed in the larger ECGviewing window at the bottom of the viewer screen as shown in FIG. 29.

FIG. 31 illustrates a feature of a constructed embodiment of the presentinvention, which is an ECG magnifier window 290. The ECG technician canright-click on an ECG strip window 292 when it is desired to view an ECGwaveform in greater detail. A list of option will appear and thetechnician selects “magnifier”, causing the circular magnifier window290 to appear. A central area of the ECG strip where the magnifierwindow 290 is located is then shown in an enlarged view in the window290. A setup option allows the user to determine the degree ofmagnification (e.g., 2×, 5×, 10×) to be provided within the magnifierwindow 290. The user can drag the magnifier window across the ECG stripwindow 292 to enlarge any section of the displayed ECG strip.

FIGS. 32-37 illustrate steps by which certain activities attendant tothe use of an ECG monitoring system of the present invention may beconducted. FIG. 32 is a sequence of steps performed when a patient isregistered for an ECG monitoring procedure. At 321 the patient'sphysician enrolls the patient with a monitoring center. Patientinformation is given to the monitoring center and the monitoring centerbegins to prepare to receive notifications from the kit to be used bythe patient. The physician may already have a kit on hand which can beused by the patient. If not, the monitoring center dispatches a kit tothe physician for use by the patient. The monitoring center associatesthe kit to be used by the patient with the patient being enrolled by thephysician. At 322 the monitoring center sets up the reportingrequirements desired by the physician using a screen such as that shownin FIG. 25. At 323 the types of arrhythmia alerts to be monitored areset up using a screen such as those shown in FIGS. 15 and 16, and alarmlimits are set as illustrated on those screens. At 324 the monitoringcenter sets up the reminder schedule for the times at which the patientwill be reminded to recharge the handset and monitor as illustrated inFIG. 24. If the physician has completed a patch position chart such asthat illustrated in FIG. 23, the chart is sent at 325 to the monitoringcenter for use by monitoring center technicians in assisting the patientwith patch application if necessary. In other instances the patchposition chart may be sent to the monitoring center at a later time. Itwill be appreciated that most or all of the information provided in thesteps of FIG. 32 may be provided by the physician completing theenrollment and setup screens remotely in the physician's office withoutperson-to-person contact with the monitoring center. That is, the setupscreens can be made available to an account of the monitoring center asa Web accessible application. Once the information has been entered at aremote terminal it is available at the monitoring center, which canprocess and enroll the patient without personal contact with thephysician.

FIG. 33 illustrates a sequence of steps performed when the patient isinitially introduced to a monitoring system of the present invention. At331 a physician or nurse turns on the cellphone handset 50 and keys thehandset to the ECG streaming mode. The monitor 30 is snapped into apatch 20 at 332 and the perforated center of the release liner isremoved from the patch to uncover the gel electrodes. If locations forpatch attachment have not previously been located on the chest of thepatient, the clinician slides and/or rotates the patch and monitor overthe patient's chest as described above to locate one or more suitablelocations and orientations for patch attachment at which a clear ECGsignal is be received, as indicated by the streaming ECG display. Assuitable chest locations are found the patch position chart is filled inat 333 to record the locations, the chart is sent to the monitoringcenter and a copy given to the patient, step 325 of FIG. 32. The releaseliner is fully removed from the patch 20 to expose the adhesive and thepatch and monitor attached to one of the ascertained locations on thepatient's chest at 334. Channels of the ECG data should now stream toand appear on the handset display 58, verifying operation of theBluetooth communication link between the monitor 30 and the cellphonehandset 50 at 335. The clinician can reset the cellphone handset tonormal operation by depressing the left “Exit” button shown in FIG. 8 band call the monitoring center at 336 to verify the second connectionlink, that between the cellphone handset and the monitoring center.Alternatively the control software of the cellphone handset can beprogrammed to make this connection automatically. A technician at themonitoring center can verify the complete communication path by, forinstance, sending a command to the monitor to transmit an ECG strip tothe monitoring center and verifying its receipt on an ECG viewer at themonitoring center. Communication with the monitoring center may indicatethe need to further reposition the monitor and patch. When the cellphonehandset 50 relays the first message from the monitor 30 to themonitoring center, the monitoring center responds by transmitting theconfiguration data for the procedure to the monitor 30. Theconfiguration data and its arrhythmia alert limits are installed in themonitor at 337 and the monitor is then ready to proceed with the study.

When it is time to exchange monitors and recharge the used monitor, thesequence of steps shown in FIG. 34 can be followed. At 341 the patientremoves the monitor 30 from the patch 20. If the patch needs to bereplaced, the patch 20 is removed from the chest and a new patchattached to a new area of the skin to avoid irritation, using the patchposition chart of FIG. 23. The monitor which was recharged the previousday and is still in the charging dock 90 is removed from the dock andsnapped into the patch at 342. The used monitor is placed into thecharging dock and the lid 102 closed at 343, and the cellphone handsetis attached to the charging cord 92 at 344. Preferably this procedure iscarried out at bedtime with the charging dock located next to thepatient's bed so that the patient can go to bed and remain withinBluetooth communication range of the charging handset 50. When thepatient gets out of bed in the morning, the charged handset is removedfrom its charging cord and put into the carrying case on the patient'swaist at 345.

It will be appreciated that the wireless communication links of thesystem, the Bluetooth link between the monitor 30 and the handset 50,and the link between the cellphone handset and a cell tower, can bedisrupted due to a variety of causes. Bluetooth communication range isusually a matter of feet, and it is generally recommended that thepatient keep the cellphone handset within six feet of the patient tomaintain this communication. If a patient puts the cellphone handsetdown and walks away for a period of time, this line of communicationwill be broken. Likewise, a patient with monitor and handset can travelout of range of a cellphone transceiver and cellphone communication willbe lost. As another example, if a patient is going to travel byairplane, aviation regulations require that the cellphone handset beturned off before the plane departs and kept off until the plane lands.Thus, cellphone communication can be intentionally unavailable for aperiod of many hours.

Disruption of the Bluetooth link does not disrupt operation of themonitor 30. The monitor will continue to receive ECG signals from thepatient and continue to analyze the heart information and store the datain the memory 216 of the monitor, even if the Bluetooth link is notoperating. If an arrhythmia event is detected it will not be possible totransmit the event data or other status message to the cellphone handset50 until the Bluetooth link is restored, however. Generally anout-of-range timeout will be allowed to expire before a loss ofBluetooth communication status message is sent to the monitoring centerby the cellphone handset to allow the activity of the patient to restorethe link before reporting the status change. When the Bluetooth link isrestored the event data and its ECG strip and all other pendingnotifications are immediately sent to the cellphone handset for relay onto the monitoring center. Preferably the Bluetooth radio is operated inthe “sniff” mode, a low power mode in which synchronization between aBluetooth transmitter and receiver can be maintained for short intervalsand quickly re-established. When the monitor has a message to send, theBluetooth transmitter is returned to full power for transmission of themessage. The Bluetooth link is operated in full duplex so that eitherthe monitor or the cellphone handset can initiate transmission of datato the other component. The monitor will continue to “sniff” for thecellphone handset while communication is disrupted so that, when thehandset is back in range, pending messages such as event and status datacan be sent to the handset and monitoring center immediately at thattime.

If the Bluetooth link is operational but cellphone service is disrupted,communication will continue between the monitor 30 and the cellphonehandset 50 so long as the cellphone handset is turned on. Event andstatus messages from the monitor will continue to be sent over theBluetooth link and received by the cellphone. However, the messages willnot be sent to the monitoring center, but will be stored in memory onthe cellphone until cellphone service is restored. When service isrestored, the messages stored on the cellphone will be immediately sentto the monitoring center at that time. It is for this reason that theflash card memory of the cellphone is of the same or greater capacity asthe memory in the monitor, 2 GB in the above example. This means that ifcellphone service is disrupted at nighttime when the day's archive datais being downloaded from the monitor, Bluetooth transmission of thearchive to the cellphone can continue even if cellphone service is down.The archive will continue to be transferred from the monitor to thecellphone handset even if cellphone service is down, since the flashcard memory 304 of the cellphone has the capacity to store the entirearchive and, in a constructed embodiment, up to several days of completearchived data. When cellphone service is restored, the cellphone willautomatically resume sending the archive data to the monitoring center.

In analyzing ECG and event data, it is important to record the times ofevents and waveforms so that all of this patient information can becorrelated to make an accurate assessment of the patient's condition.This means that the information must be time-stamped with the time ofoccurrence of the information and that the information be related to acommon time base. The patient data could be time-stamped at the time ofits receipt at the monitoring center and related to a common time basethere, however, as just mentioned, the wireless communication links canbe interrupted, thereby delaying the receipt of data at the monitoringcenter and resulting in erroneous time stamps. Each monitor has its owntime base and on-board clock, and this clock could be used to time-stampdata before it is stored in the monitor's memory or sent to themonitoring center. The monitoring center would thereby have a commontime base for data received from a monitor. However, the kit of thepreferred embodiment uses two monitors which are exchanged each day,each monitor with its own clock. Accordingly, the clocks of the twomonitors could be synchronized prior to delivery of the kit to thepatient. But clocks can drift over time, and the two clocks of the twomonitors could drift at different rates over time, causing a time basedisparity between the two clocks. In the preferred embodiment theseproblems are addressed, not by adjusting the monitor clocks, but byrelating the patient data to the time base of the cellphone network. Thecellphone handset periodically sends its cellular network-based time tothe monitor(s). When the cellphone time is received by a monitor, themonitor stores the cellphone time and the current monitor time as partof the patient data. When the monitoring center receives the data withthis timestamp information, it can correlate the patient data to thecellphone network-based time. The monitoring center, having access tothe cellphone network and its time base, can relate the patient data andits cellphone network-based time stamps to its own time base if desired.In this way the data produced by multiple monitors used by a patient isrelated to a common and reliable time base.

As mentioned above, in a constructed embodiment of the present inventionthere are only two buttons for the patient to operate on the cellphonehandset, 62 and 64 as shown in FIG. 6. As previously mentioned, thedefault functions of these buttons are “Call for Help” and “RecordVoice,” as indicated by the softkey legends on the screen 58 above thebuttons. FIG. 35 provides an example of how the “Call for Help” buttoncan be used in an embodiment of the present invention. The patient willgenerally be instructed to use the Call for Help button whenever thepatient has a problem or question about the monitoring system or has amedical emergency. In either of those situations the patient willdepress the Call for Help button 64 on the handset 50, and the cellphonehandset will call the monitoring center at 352, the only number it cancall in this embodiment. As the call is placed, the monitor 30 isprompted at 354 to begin transmission of an ECG strip to the monitoringcenter for a 90-second period commencing before the time of the call andcontinuing for a period of time thereafter. A medical technician at themonitoring center will answer the voice call at 356 and begin talking tothe patient. While the technician is talking to the patient he can viewthe concurrent ECG strip so that the ECG data can be viewed if thepatient is calling with a medical problem. In a constructed embodimentof the present invention the technician and the patient can engage in avoice communication at the same time as the ECG strip data is being sentto the monitoring center; it is not necessary to end the voice call sothat the ECG data can be sent. If the patient has a question about themonitoring system the question will be asked of the technician asindicated at 358. The technician will provide the requested informationor guidance so that the patient can continue to effectively use themonitoring system. If the call is being made in a medical emergency, thetechnician may call the 911 emergency response system for aid or ifappropriate under the conditions, call the patient's physician about thesituation. This call-for-help service from the monitoring center shouldbe available to the patient 24 hours a day and seven days a week.

FIG. 36 gives an example of the use of the “Record Voice” button 62 ofthe handset 50. When the patient feels a cardiac symptom as directed byhis physician, the patient will use the monitoring system as an eventrecorder by depressing the Record Voice button at 362. When the buttonis depressed the patient will listen to instructions from the handsetand be told to record a message when the cellphone handset is programmedwith these functions. In other embodiments the recording instructionsmay be provided in a printed user guide supplied with the monitoringkit. If the message has a predetermined maximum length, the patient willbe told not to exceed this length or to record a second message ifgreater recording time is needed. This information may be providedvisually or audibly. As the patient speaks into the cellphone microphonethe patient's voice is recorded by the cellphone at 366. The depressionof the Record Voice button will also cause a command to be issued to themonitor 30 to send a 90-second ECG strip encompassing the time of thevoice message at 364. The recorded voice message and the concurrent ECGstrip are sent to the monitoring center by the cellphone handset, wherean ECG technician can listen to the recorded message from the patientand simultaneously analyze the data of the ECG strip with the ECGviewer.

FIG. 37 provides an example of how the monitoring center may respond toa problem reported by the monitoring system. At 372 the monitoringcenter receives a status notification from the patient's monitor. Asmentioned above, in a preferred embodiment the monitor sends a statusmessage to the monitoring center whenever the status of the monitorchanges. The status notification may be that an electrode has come loosefrom the patient's skin or that the monitor has been placed in thecharging dock, for example. In the case of these two examples, thecellphone handset alerts the patient that an error condition needsattention and the patient can resolve the problem without interventionby the monitoring center. When a loose electrode is detected by themonitor 30, a message is sent to the cellphone handset 50 and a graphicappears on the cellphone display 58 as illustrated by FIG. 8 h,informing the patient of the problem and illustrating how to resolve theproblem. The display is accompanied by a tone or beep from the handset,drawing the patient's attention to the displayed message, and may alsobe accompanied by a voice prompt instructing the patient to take thenecessary action. If the patient is unsure what to do, the patient maypress an information button “i” on the handset in embodiments havingthis button, and a context-based voice message is played with adescription of the problem shown in the graphic and its resolution.However it is possible that the patient may not notice these messagesand the situation continues unresolved; the patient may be asleep, forinstance. In such instances the monitoring center may wait a period oftime after receipt of the status notification for the patient to resolvethe problem. If a period of time has passed without resolution, the ECGviewer may escalate the notification to a higher priority, at whichpoint the monitoring center takes action. The technician at themonitoring center places a call to the patient over the cellphonehandset at 374. When the patient answers the cellphone, the technicianand the patient discuss the problem and the technician can guide thepatient in the resolution of the issue at 376. In this example theresolution may entail replacement of the patch 20 with a new patch, forinstance.

In the second example, the patient may have placed the monitor 30 in thecharging dock 90 for recharging but forgotten to close the lid 102,which is necessary for recharging to commence in this example. Byimpedance measurement of the contact engagement the charging dock ormonitor will detect that the lid has not been closed to press themonitor into firm engagement with the elastomeric contacts of thecharging dock. In other embodiments a switch in the charging dock candetect that the lid has not been closed and a message sent to themonitor of the condition for relay on to the monitoring center. A statusnotification sent from the monitor is received by the monitoring centerat 372, notifying the monitoring center that the monitor has beenremoved from the patch and/or placed in the charging dock but thatrecharging has not commenced. The patient is informed locally of thisproblem, either by the absence of the green charging light in thecharging dock or by display or flashing of the LED light 104 of thecharging dock in a warning color such as alternate orange and greenflashing. A graphic and tone or voice prompt can also be displayed andissued from the cellphone handset 50, alerting the patient to theproblem. But if the patient does not tend to the problem after a periodof time, the notification received by the monitoring center is escalatedto a higher priority on the ECG viewer, at which point the monitoringcenter can take action. A technician at the monitoring center calls thepatient on the cellphone handset 50 and discusses the situation with thepatient at 374. The patient and the monitoring center will then resolvethe situation by the voice call at 376 when the patient closes the lid102 of the charging dock and charging of the monitor begins.

For other notifications received by the monitoring center, no patientinvolvement is needed or appropriate. For instance, if at the end ofrecharging and archive transmission the self-tests performed by themonitor reveal an error condition in the monitor, the LED light 104 onthe charging dock 90 will begin to flash alternately green and orange,informing the patient to contact the monitoring center by using the“Call for Help” button 64 on the cellphone handset. The result of theself-test will also cause the monitor 30 to send a notification of theself-test result to the monitoring center, and if the error conditiondoes not prevent the transmission of the notification, the monitoringcenter is informed of the problem when the notification is received. Atechnician at the monitoring center will see the notification and, ifthe reported condition requires attention, the technician cansubsequently call the patient's cellphone handset 50 and instruct thepatient to take appropriate action. A replacement monitor may bedispatched to the patient by express courier to replace the monitor withthe error condition, for instance. In this case the patient will beinstructed to begin using the replacement monitor and to send themonitor with the error condition back to the monitoring center. In otherembodiments the patient is provided with both a new monitor and a newcellphone handset which have been Bluetooth-paired. Another alternativeis to download the Bluetooth pairing data to the monitor and handsetfrom the monitoring center.

A procedure or study conducted with a monitoring system of the presentinvention will generally continue for twenty-one to thirty days, onaverage. At the end of the study the patient will return the kitcomponents for reuse by other patients. The patient can take the kitback to the patient's physician at the next office visit, but preferablythe kit is supplied with a pre-addressed, postage-paid shippingcontainer or envelope for return of the kit as soon as the study isconcluded. The kit can be returned to the monitoring center where it isprepared for the next patient, but preferably the kit is returned to arefurbishment center which specializes in inspecting and preparing kitsfor subsequent patients. FIG. 38 illustrates some of the proceduresperformed by such a refurbishment center in preparing a kit for reuse.At 380 the kit is received at a refurbishment center from a postalcarrier or transport service. The kit components are unpacked,disinfected at 382 to safeguard against possible exposure to infectiousdisease, and inventoried to determine that all of the kit componentshave been returned. A database with screens such as those shown in FIGS.18, 20 and 22 may be used to log the receipt of the returned kit and itsmonitors and cellphone handset. If a component is missing the patient orphysician is contacted so that the missing component can be returned tothe refurbishment center. At 384 the monitor and cell phone batteriesare charged, and the batteries of the monitors and cellphone handset arechecked at 386 to ensure that they can continue to be recharged tonecessary levels during the next study. At 388 any patient data stillresident in the memories 216 and 304 of the monitors and cellphonehandset is cleared for protection of patient privacy. At 390 thecomponents are self-tested and the self-test results verified. At 392the kit components are inspected and tested to verify their operabilityaccording to specifications. At 394 the software of the charging dock90, the cellphone handset 50 and the monitors 30 is upgraded if upgradeshave become available. As previously mentioned in conjunction with FIG.12 b, in a preferred embodiment the monitors 30 have a USB portaccessible through the contacts on the back of the monitor case. Newsoftware can be loaded into the monitor by this USB connection. It mayalso be desirable to re-image the data storage of these devices eachtime to ensure a fresh software start for each patient. The kitcomponents can be reassembled into a kit at 396 and the kit put backinto inventory for subsequent delivery to a new patient. In a preferredembodiment a kit includes two monitors 30, a cellphone handset 50 withcover 56, a charging dock 90 with cellphone charging cord 92 and a powercord, a carrying case for the cellphone handset, a number of patches 20,and a user guide with instructions for the patient. Preferably the kitis delivered to the patient in a box or case which is suitable forshipping the kit back to the refurbishment center, monitoring center, orphysician in the same box or case in which the kit was supplied to thepatient. Alternatively as indicated at 398, the individual kitcomponents can be put back into inventory for subsequent assembly into akit as described in conjunction with FIG. 17.

Other variations and features for the present invention will readilyoccur to those skilled in the art. For instance, cellphones arecommercially available with built-in GPS receivers which identify thegeographical location of the cellphones. The use of such a cellphone inan implementation of the present invention would enable the location ofthe cellphone handset to be communicated to the monitoring center,enabling the monitoring center to direct medical assistance to the exactlocation of the patient if a life-threatening arrhythmia or othermedical emergency occurred. Alternatively, cellular triangulationtechniques could be used to ascertain the patient's location. Forexample, if the monitoring center receives an Event notification and ECGstrip indicating the occurrence of a serious cardiac event, thetechnician at the monitoring center will immediately call the patient'scellphone handset to see if the patient needs medical aid. However, thecardiac event may have rendered the patient unconscious and incapable ofanswering the call from the monitoring center. The control software ofthe cellphone handset is programmed to answer a call from the monitoringcenter after a predetermined number of rings, so the connection betweenthe monitoring center and the patient's cellphone will be establishedeven if the patient does not answer the cellphone. In the United Statesthe technician at the monitoring center can then call the local 911emergency response service, which is able to pinpoint the patient'slocation from the connection between the monitoring center and thepatient's cellphone handset. Medical assistance can be immediatelydispatched to the identified location of the stricken patient.

1. A method for configuring a cardiac monitoring system for detection ofa predetermined arrhythmia of an ambulatory patient, the cardiacmonitoring system including a battery powered ECG monitor worn by thepatient and having a patient ECG signal processor, arrhythmia detector,and a wireless transceiver for sending status messages and receivingarrhythmia detector configuration information, the cardiac monitoringsystem further including a cellphone handset having cellphoneelectronics operable for communication with a monitoring center over acellular network, a transceiver for wirelessly communicating with theECG monitor, and a controller operable to cause the cellphone handset toforward status messages received from the ECG monitor to the monitoringcenter and to forward to the ECG monitor configuration informationreceived from the monitoring center, the method comprising: determining,prior to cardiac monitoring of a patient, a parameter of a predeterminedarrhythmia which is to be detected and storing the parameter in aconfiguration file at the monitoring center; attaching the ECG monitorto the patient to begin ECG monitoring; sending a status message fromthe ECG monitor to the monitoring center in response to the commencementof ECG monitoring; responding to the status message by sending theconfiguration file to the ECG monitor; and using the configuration fileto configure the arrhythmia detector.
 2. The method of claim 1 whereindetermining further comprises determining one or more alarm limits forone or more arrhythmias which are to be detected by the arrhythmiadetector.
 3. The method of claim 2, wherein determining furthercomprises: displaying on a computer display a plurality of selectablearrhythmias with selectable alarm limits.
 4. The method of claim 3,wherein the alarm limits comprise one of more of beats per minute (BPM),time, or priority.
 5. The method of claim 3, wherein displaying furthercomprises displaying a custom alarm which may be selected and configuredby an operator.
 6. The method of claim 1, further comprising: checkingfor an updated configuration file each time a message is sent to themonitoring center during ECG monitoring.
 7. The method of claim 1,wherein using further comprises: detecting an arrhythmia when anarrhythmia identified in the configuration file meets or exceeds analarm limit for the arrhythmia identified in the configuration file; andsending an event notification message to the monitoring center when anarrhythmia is detected.
 8. The method of claim 7, wherein sending anevent notification message further comprises: sending a concurrent ECGstrip to the monitoring center.
 9. The method of claim 1, furthercomprising: after an ECG monitoring procedure has commenced, displayingon a computer display a plurality of selected arrhythmias with selectedalarm limits of the configuration file for the procedure; changing oneor more of a selected arrhythmia or a selected alarm limit of theconfiguration file; transmitting the modified configuration file to theECG monitor; and using the modified configuration file to configure thearrhythmia detector.
 10. A method for configuring a cardiac monitoringsystem for detection of a predetermined arrhythmia of an ambulatorypatient, the cardiac monitoring system including a battery powered ECGmonitor worn by the patient and having a patient ECG signal processor,arrhythmia detector, and a wireless transceiver for sending messages toand receiving arrhythmia detector configuration information from amonitoring center, the method comprising: determining, prior to cardiacmonitoring of a patient, an alarm limit of a predetermined arrhythmiawhich is to be detected and storing the alarm limit in a configurationfile at the monitoring center; activating the ECG monitor; sending amessage over a wireless communication link from the ECG monitor to themonitoring center; responding to the message by sending theconfiguration file over a wireless communication link to the ECGmonitor; and using the configuration file in the ECG monitor toconfigure the arrhythmia detector.
 11. The method of claim 11, whereinactivating comprises commencing an ECG monitoring procedure with apatient.
 12. The method of claim 11, wherein activating furthercomprises receiving patient ECG signals with the ECG monitor.
 13. Themethod of claim 10, wherein determining further comprises: displaying ona computer display a plurality of selectable arrhythmias with selectablealarm limits; selecting one or more arrhythmias with one or more alarmlimits for detection; and storing the selected arrhythmias and alarmlimits in a configuration file.
 14. The method of claim 13, whereindisplaying further comprises displaying a custom alarm which may beselected and configured by an operator.
 15. The method of claim 10,further comprising: checking for an updated configuration file each timea message is sent to the monitoring center during ECG monitoring. 16.The method of claim 10, wherein using further comprises: detecting anarrhythmia when an arrhythmia identified in the configuration file meetsor exceeds an alarm limit for the arrhythmia identified in theconfiguration file; and sending an event notification message to themonitoring center when an arrhythmia is detected.
 17. The method ofclaim 16, wherein sending an event notification message furthercomprises: sending a concurrent ECG strip to the monitoring center. 18.The method of claim 10, further comprising: after an ECG monitoringprocedure has commenced, displaying on a computer display a plurality ofselected arrhythmias with selected alarm limits of the configurationfile for the procedure; changing one or more of a selected arrhythmia ora selected alarm limit of the configuration file; transmitting themodified configuration file to the ECG monitor; and using the modifiedconfiguration file to configure the arrhythmia detector.